Winding machine



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WINDING MACHINE Filed March 26, 1964 4 Sheets-Sheet 3 INVENTOR. [THE/06E 5 IVA/Q0657) 56.4. I A BY y 1968 E. E. HARDESTY 3,391,873

WINDING MACHINE Filed March 26, 1964 4 Sheets-Sheet 4 INVENTOR. 7//?/06 5 #420557) ATTQP/VE/f United States Patent 3,391,873 WINDING MACI-HNE Etheridge E. Hardesty, Pine Valley, Calif., assignor to Swedlow, Inc., Los Angeles, Calif., a corporation of Ca ifornia Filed Mar. 25, 1964, Ser. No. 355,014 9 Claims. (Cl. 242-2) This invention relates to rocket engines and more particularly relates to apparatus for winding a filament casing for a solid propellant rocket motor.

As rocket motors become larger and larger, it becomes progressively more difiicult to transport them from a place of assembly to the launching pad. This is particularly true of solid propellant rocket motors because of the nature of the propellant and the hazards inherent in its handling. It has been proposed that solid propellant rocket motors be cast in a single monolith or constructed by assembling large segments of precast solid propellant into a stacked configuration, the segments taking the shape of pie wedges, cored dis-ks, solid disks and the like.

It has further been proposed that a seamless, jointless encompassing structural shell may be formed about the solid propellant by wrapping the propellant with a suitable filament, the propellant itself serving as an integral, shapedefining mandrel. However, no suitable apparatus has been proposed for winding the propellant, particularly when the solid propellant motor is composed of a number of relatively loose and unconnected, or at the most only superficially connected, individual blocks of cast propellant, as the accepted manner of revolving mandrels during conventional winding is unsuited to such a delicate operation.

Another method of constructing such rocket motors also requires that a shell or casing be wound to contain the solid propellant. In this method, an expendable winding mandrel which conforms to the desired inside shape of the casing is constructed by assembling a network of metal staves which are braced to a main axial member. A soluble plaster is screeded over this metal form to provide a smooth inside-shape-defining form. The motor case is then wound over this form to the proper thickness and shape. The mandrel supported layup of reinforced plastic is then placed in an oven to cure the binder resin into insolubility. Water is then used to soften and remove the mandrels plaster. The metal stiffeners and ribs in the mandrel are then unbolted and lifted out through the nozzle opening.

According to the present invention, apparatus is provided for winding a casing for a solid propellant rocket motor regardless of the manner in which it is constructed. The apparatus is particularly useful for winding such a motor where the mandrel used is the solid propellant itself, as it enables the winding to be done right on the launching pad thereby eliminating the necessity of transporting the assembled motor. The foregoing is accomplished by providing apparatus that can be moved to encircle a stack of propellant assembled on the launching pad and which does not disturb the propellant as it forms an outer casing thereon. The apparatus cures the filamer binder resin without adding heat to the propellant, winds in integral skirts, finishes the motor case and can then be dismantled for removal to a different location. The apparatus is equally useful for winding a casing on an expendable mandrel, either on a launching pad or in some other location. The winding mechanisms of the apparatus are moveable in two cooperating axes of rotation and may be programmed to properly compensate for the no:- zle attach area at the end of the mandrel, whether it be a stack of ropellant or an expendable mandrel.

It is therefore an object of the present invention to provide apparatus for winding an outer casing for a solid propellant rocket motor.

It is also an object of the present invention to provide apparatus for winding a filament casing about the exterior of a solid propellant rocket motor positioned on a launching pad.

It is another object of the present invention to provide a winding machine that will wind any desired filament pattern on an immovable mandrel.

It is a further object of the present invention to provide a winding machine for solid propellant rocket motors that will alternately wind a longitudinal pattern and a circumferential pattern on an immovable mandrel and which will compensate for the presence of nozzle attach areas.

These and other objects and advantages of the present invention will become more apparent upon reference to the accompanying description and drawings in which:

FIGURE 1 is a perspective view of the framework for the present winding machine being moved into place;

FIGURE 2 is a side elevation of the apparatus of the present invention;

FIGURE 3 is a view taken substantially along lines 3-3 of FIGURE 2;

FIGURE 4 is a view taken substantially along lines 44 of FIGURE 2;

FIGURE 5 is a side view of a modified use of the apparatus shown in FIGURE 2;

FIGURE 6 is an enlargement of a view taken substantially along lines 66 of FIGURE 2;

FIGURE 7 is a view taken substantially along lines 7-7 of FIGURE 6;

FIGURE 8 is a view taken substantially along lines 88 of FIGURE 7;

FIGURES 9 and 10 show various winding patterns which can be formed by the apparatus of FIGURE 2; and

FIGURE 11 shows a portion of a solid propellant rocket motor wound in the manner illustrated by the apparatus shown in FIGURE 5.

Referring now to FIGURE 1, there is shown a mandrel 20 which is illustrated as a single monolith of solid propellant but which may also be a stack of suitable segments or a pro-assembled, removable mandrel. The propellant 20 is positioned on a nozzle assembly 21 which in turn is located on a launching pad 22. A framework 23 having a roof 24 is mounted on a suitable trailer or dolly 25 which can be moved into position around the propellant by a truck 26. The framework 23 is provided with a hinged section 27 which enables the framework to be positioned about the propellant and then swung closed to provide a framework completely enclosing the propellant. The framework can be removed from the dolly 25 and securely maintained in place by any conventional means such as guy-wires or the like.

Referring now to FIGURES 2, 3, 4, 6, 7 and 8, there is shown apparatus capable of winding a plurality of different patterns of filament on a solid propellant rocket motor. As can be seen from FIGURE 2, the framework 23 is constructed from a plurality of steel tubing sections 36 preferably joined by conventional quick-connection joints. Other suitable structural members could, of course, be used in place of the tubing sections. The various tubing members may be reinforced by steel tension rods 31 provided with conventional turnbuckles. The framework 23 may, if desired, be enclosed by a plurality of lightweight translucent plastic panels or suitable weather sheathing.

A plurality of brackets 32 are mounted near the top of a number of the main framework columns and serve to support an annular decking 33 constructed of steel mesh or the like. A steel ring 34 is mounted on the platform 33, the ring preferably beingfabricated in a plurality of sections for ease of assembling. The ring 34 serves as a base for a steel rail 35 rolled in a ring. The rail 35 may be of any known type but preferably has a cross section similar to the standard railroad rail. The ring 34 is provided with a ring gear 36 on its outer periphery for cooperating with a turntable bridge structure generally indicated at 39.

As best seen in FIGURES 2 and 3, the turntable bridge 39 includes a pair of I-beams 40 and 41 which are joined at their centers by an I-beam 42. A pair of 'I-bearns 43 and 44 are fastened to one end of the I-beams 40 and 41 while another pair of I-beams 45 and 46 are fastened to the other ends of the beams 40 and 41, the whole assemblage thus generally taking the form of an H. This H-shaped assembly is provided on its lower side with a plurality of housings 47, 48, 49, and 50. Mounted for rotation in these housings are flanged roller bearing wheels 51, 52, 53 and 54 which are adapted to roll along the rail 35. -A platform 55 of any suitable type is fastened to the I-beam 43 and mounts a motor 56 whose output shaft drives a pinion gear '57. This pinion gear '57 cooperates with the ring gear 36 on the ring 34 to move the turntable bridge relative to the framework 23.

A plurality of columns 62 constructed of steel tubing sections are fastened to the I-beams 43, 44, 45 and 46 and depend therefrom and are provided with suitable cross braces 63 and '64 to provide structural strength and rigidity. Only representative columns are shown in the interest of clarity, but it should be understood that any suitable structure could be used to perform the function of these columns. A plate 66 is welded or otherwise fastened to the bottoms of the columns 62 depending from the I-beams 45 and 46 and supports a plurality of generally J-shaped mounts 67 each of which serves as a housing to support the axles of a pair of rollers 68 and 69 which rotate in the same plane but which are spaced apart. The rollers 68 and 69 cooperate with an angle beam 70 rolled in the form of a ring and supported from the main framework 23 by a plurality of braces 71 to stabilize the lower end of the rotatable structure.

The turntable bridge 39 also supports a boom 72 on which rides an operators elevator 73 driven for example, by any suitable motor 74 which may, for example, be electrical, hydraulic or pneumatic. The boom 72 may, for example, be fixedly attached to the I-beam 43 by any of the means conventional in the art. The elevator preferably is of the type that may be controlled by the operator carried thereby.

The turntable bridge 39 serves to support a winding track assembly generally indicated at 80. As can be seen from FIGURE 4, the track 80 is preferably made of a plurality of straight sections 81 and curved sections 82 so that its averall size can be altered to adapt it for use with any size rocket motor. The winding track assembly 80 is provided with an upper pair of projecting structural members 83 and a similar lower pair of members 89 which are used to connect the winding track assembly to the structural members 62 attached to and depending from the turntable bridge 39.

For this purpose, the upper members 83 are each connected to a motorized linkage 84 of conventional design while each of the lower members 89 are pivotally connected to the plate 66 by a conventional pivot-bearing assembly 85. The members 83 and 84 may simply be tubular members with a cross piece at their outer ends for connection to the linkage 84 and the pivot-bearing assembly 85. The motorized linkage 84 and ivot-bearing assembly enable the winding track assembly to be tilted relative to the vertical for a purpose to be explained hereinafter.

A plurality of winding carriages 86 are mounted for movement on the winding track assembly which, for this purpose. is provided with a guide rail 87 and a drive chain 88. The structure of the winding carriages 86 and the manner in which they are propelled about the winding track assembly is shown in more detail in FIG- URES 6, 7 and 8.

As best shown in FIGURES 6 and 7, the winding carriages 86 each include a horizontal frame preferably constructed of aluminum channels 90 welded together in the form of a rectangle. A pair of supporting members 91 and 92, preferably constructed of aluminum tubing, form a triangle whose apex is joined to a horizontal member 94 fastened to this supporting triangle by any suitable means and given additional strength by means of a conventional brace 95.

The member 94 supports a trunnion bearing 96 on its outer end. Pivotally mounted in the trunnion bearing 96 is a generally L-shaped member 100- preferably formed of welded aluminum tubing. The other end of the member 100 is rigidly fixed to a plate 101 which supports a rack 102. A member 103 directly connects the upper end of the member 100 with the upper end of the plate 101 to provide additional structural strength.

A second pair of structural members 104 and 105 form a second triangle the apex of which is rigidly fastened to a second horizontal member 106 which supports a second trunnion bearing 107 vertically aligned with the trunnion bearing 96. The member 106 may also be given additional support by a conventional brace 108. The tubular member 109 is pivotally mounted in the trunnion bearing 107 and is attached by means of members 110, 111, and 112 to the lower end of the plate 101. Further structural support can be provided by a member 113 which extends directly between the member 109 and the lower end of the plate 101. A gusset plate 114 can also be provided between the members and 111 to further strengthen the assembly.

A plurality of axles 115 are mounted in any conventional manner in the rack 102 and have mounted thereon a plurality of filament spools 116. The filament used is preferably made of glass fibers and coated with an epoxy 'resin such as F.M.C. Oxiron 2000 or other suitable binder. Other filamental materials such as metal wire or graphite or combinations thereof could also be used. The filament from each of the spools 116 is fed over a corresponding ball bearing mounted guide roller 117 to a ball bearing mounted payout guide roller 118 supported for rotation in a housing 119 mounted on the member 109. The guide rollers 117 are staggered so that the various filaments are fed to the payout guide roller 118 side by side to form a single tape which may then be fed through a suitable heater 121 which is supported by a member 122 attached to the housing 119 and trailing behind it. The heater causes the binder resin on the various filaments to soften and intermix so that a single tape 123 is formed when the resin cures. The tape 123 leaving the heater 121 is wound on the rocket motor in the manner shown in FIGURE 9 or 10. This apparatus thus provides a filament casing material of great strength without requiring the later application of heat to the casing, which, of course, would be a very hazardous operation.

Each of the spools 116 is provide-d with an individual, adjustable tension control 124. A tachometer generator 125 is mounted on the housing 119 and driven by the payout guide roller 118 to produce a reference signal for the individual tension controllers 124. The specific structures of these individual components and the electronic circuitry used in their control are well known and form no part of the present invention. A cabinet 126 is mounted on the horizontal framework of the Winding carriage to enclose the various low energy electrical components of the electronic tension control system.

In order that the winding arms of the winding carriages can be used for either longitudinal or circumferential winding patterns, an index plate 127 is mounted on the top of the pivotally mounted member 100 and cooperates with an index lock 128 mounted on the member 94. This lock may consist simply of a plate provided with a threaded aperture suitable for receiving a bolt 129 dropped through any of a series of holes 130 provided in the plate 127 to maintain the plate 127 and hence the tubular member 100 in a fixed relationship with the member 94.

The Winding carriage 86 is provided with a pair of downwardly depending plates 134 and 135 attached to the channels 90. These plates serve to support axles 136 and 137 respectively. Mounted on the axle 136 is a grooved wheel 138 which cooperates with the track 87 to guide the winding carriage along a proper path. A Wheel 139 the same size as the wheel 138 but without a groove is mounted on the axle 137 and rolls along the surface of the track assembly In order to maintain the carriage on the track the carriage is provided with a pair of pneumatic or similar resilient, local-roughness-absorbing tires 140 and 141 mounted on wheels which rotate about axles 142 and 143. These axles are supported by plates 144 and 145 which are adapted to be positioned flush with the plates 134- and 135 by means of hinged members 146 and 147. These hinges are locked in the position shown in FIGURE 7 when the carriage is to ride on the track and when it is to be removed the hinges can be bent back so that the carriage may simply be lifted off the track.

The winding carriages are driven by means of a motor 150 which has a pinion gear 151 mounted on its output shaft. This pinion gear cooperates with a ring gear 152 mounted on a sprocket 153. The sprocket 153 is mounted for rotation in a housing 154 which is fastened to the bottom of the track in a manner which enables the sprocket to continually move the chain 88. Each winding carriage can be provided with a trailing link 155 which can be engaged with the chain 88 when it is desired that the winding carriage move relative to the track assembly. The motor is, of course, mounted on the track assembly in any suitable position.

In the operation of the winding apparatus just described, a helical winding having any helix angle may be wound on a solid propellant rocket motor. Thus the pattern may be essentially circumferential or essentially longitudinal. The angle at which the pattern is wound is determined by the relative speeds of the winding carriages movement about the track assembly 80 and the rotational movement of the track assembly caused by the rotation of the turntable bridge 39. If it is desired to produce a longitudinal pattern, the winding arms are locked in the position shown in the several figures and the Winding carriages moved at high speed around the winding track assembly 80 relative to the rotational speed of the turntable bridge 39. As may be seen from FIGURES 2 and 4, all of the carriages are made operative for a longitudinal wrap with the resulting pattern resembling that shown in FIG- URE 10.

If, on the other hand, it is desired to produce a circumferential pattern, the winding arms are swung and locked approximately 90 from the position shown and the turntable bridge 39 rotated at a high rate of speed relative to the speed of the winding carriages moving along the track assembly 89. Less than the full number of winding carriages may be used to carry out a. winding operation; for example, it is generally preferred to use only two carriages for a circumferential Wrap, the remainder of the winding carriages being rendered inoperative. Such an operation will result in a winding pattern having the form shown in FIGURE 9, the layers passing each other at midpoint and continuing to the other end, thus laying down a doublethickness layer.

In actual practice, of course, circumferential and longitudinal patterns are wound alternately on each motor.

When the apparatus is set for a longitudinal winding pattern, there will naturally be a glass fiber buildup over the ends of the rocket motor. While this is desirable at the lower or nozzle attach area of the motor to distribute stresses around the opening provided for the nozzle, it is not desirable for the upper end of the motor which has only a small opening or no opening at all. The tilting linkage 84 and pivot bearing assembly 85 are therefore provided to distribute the usual buildup evenly over the upper end of the motor. The operation of this tilting linkage can be programmed by conventional electronic or mechanical equipment to tilt the track at the completion of each longitudinal layer to alter the angle sufficiently to lay the next rope or tape alongside the previous one without the concentrated overlapping at the center that would normally occur. This equipment, and all the electrical equipment used, may if desired be controlled from a main console 156 by a second operator. Electrical connections may be by suitable flexible cables as are well known to those skilled in the art. All electrical equipment, of course, should be of the type approved for use in hazardous locations.

FIGURES 5 and 11 illustrate a somewhat different manner in which a solid propellant rocket motor may be wound. in this embodiment, the solid propellant segments are separated from each other by a filament coating rather than bein concurrently wound while in engagement with each other. As may be seen from FIGURE 5, the straight sections 81 of the track assembly 80 are initially removed and only the curved sections 82 utilized, and fewer winding carriages 86 are used. A first hemispheroidal block of propellant 157 is placed in a bowl-shaped insulating member 153 suitably supported by a nozzle assembly 159, and wound in with longitudinal and circumferential windings. The next segmental block of propellant is then placed on top of the wound first segment and the Winding operation repeated. Each added segment of propellant is wound in sequentially until the required number have been added, the last section or cap piece, like the first, being hemispheroidal. The track assembly 80 is expanded when necessary by the addition of straight sections 81. FIGURE 11 shows a portion of a rocket motor resulting from such a procedure.

This method has certain advantages, the foremost being that each segment is firmly fixed and supported before the next is added. Also, this method of winding results in a tapered wall case construction, with increasing shell thickness toward the aft, or nozzle, end. Such a tapered construction has been found to have structural advantages in some applications.

After the winding has been completed, the winding track assembly can be removed from the turntable bridge and the elevator and turntable bridge used to perform further operations on the rocket motor, such as wrapping it with external insulation, smoothing the windings to provide an aerodynamically clean exterior surface and the like. The elevator could also be provided with machining equipment which could be used before the Winding operation to trim the propellant to establish concentricity of the segments and improve their fit. The framework could also be used to house and support a gantry crane for initially stacking the propellant segments.

From the foregoing description it can be seen that a novel apparatus has been provided for winding a suitable filament cover for a solid propellant rocket motor while the motor stands immovable on the launching pad. This apparatus eliminates the need for transporting the finished rocket motor from an assembly point to the launching pad and thus makes larger size rocket motor feasible, as well as being more convenient for any size rocket motor. The winding apparatus is suspended from a framework above the rocket motor and moves about the motor, thus eliminating the problem of rotating a somewhat delicately balanced mass of propellant. The movement of winding carriages about the suspended apparatus in a plane intersecting the plane of rotation permits any desired winding pattern to be eaisly obtained.

The invention may be embodied in other specific forms not departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the

scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim: 1. Apparatus for winding a filament casing on a stationary object, comprising:

a framework positionable adjacent said object; means mounted on said framework above said object, said means including means rotatable completely around said object; track means suspended from said movable means, said track means being positionable about said object; means for laying a filament on said object, said filament laying means being mounted on said track means for travel thereon; and means for varying the angle between said track means and said movable means. 2. Apparatus for winding a filament casing on an object, comprising:

a framework positionable adjacent said object; a continuous rail mounted on said framework above said object and extending around said object; turntable means movable on said rail; track means mounted on said turntable means and depending therefrom, said track means being positionable about said object; and means for laying a filament on said object, said filament laying means being mounted on said track means for travel thereon. 3. Apparatus for winding a filament casing on an object, comprising:

a framework positionable adjacent said object; a circular rail mounted on said framework above said object; a turntable mounted for movement on said rail; track means suspended from said turntable, said track means being positionable about said object whereby said track means is rotated about said object by movement of said turntable; and means for laying a filament on said object, said filament laying means being mounted on said track means for travel thereon, whereby movement of said filament laying means along said track means causes filament to be laid in a generally longitudinal direction on said object and movement of said track means causes filament to be laid in a generally circumferential direction on said object. 4. Apparatus for winding a filament casing on an object, comprising:

a framework positionable adjacent said object; a circular rail mounted on said framework above said object; a turntable mounted for movement on said rail; a support suspended from said turntable; track means mounted on said support adjacent said object and at an angle with the vertical; means connected to said support and to said track means for varying said angle; and means for laying a filament on said object, said filament laying means being mounted on said track means for travel thereon whereby the filament pattern laid on said object is dependent on the speed of movement of said turntable on said rail and said filament laying means on said track. 5. Apparatus for winding a filament casing on a stationary object, comprising:

a framework positionable about said object; a circular rail mounted on said framework above said object; a turntable mounted for movement on said rail; means for moving said turntable on said rail; a support suspended from said turntable; track means mounted on said support at an angle with the vertical and about said object whereby said track means is rotated about said object by movement of said turntable;

means for laying a filament on said object, said filament laying means being mounted on said track means for movement in the plane of said track means; and

means for moving said filament laying means in the plane of said track means.

6. Apparatus for winding a filament casing on a stationary object, comprising:

a framework positionable about said object;

a circular rail mounted on said framework above said object;

a turntable mounted for movement on said rail;

means for moving said turntable on said rail;

a support suspended from said turntable;

track means mounted on said support at an angle with the vertical and positioned about said object whereby said track means is rotated about said object by movement of said turntable;

a plurality of filament laying means mounted on said track means for movement in the plane of said track means whereby movement of said filament laying means in the plane of said track means causes filament to be laid in a generally longitudinal direction on said object and rotation of said track means causes filament to be laid in a generally circumferential direction on said object; and

means for moving said filament laying means in the plane of said track means.

7. The apparatus of claim 6 wherein means are connected to said support and to said track means for vary: ing said angle between said track means and the vertical.

8. Apparatus for winding a filament casing on a stationary solid propellant rocket motor, comprising:

a framework positionable about said motor;

first and second rails mounted on said framework, said first rail being positioned above said motor;

a turntable mounted for movement on said first rail;

means for moving said turntable on said rail, said means including motor means mounted on said turntable;

a support suspended from said turntable, said support having means at its lower end for cooperating with said second rail to stablize said support;

track means mounted on said support at an angle with the vertical and positioned about said motor whereby said track means is rotated about said motor by movement of said turntable;

a plurality of filament laying means mounted on said track means for movement in the plane of said track means, said filament laying means having a first position for laying filament on said motor in a plane parallel to the plane of said track means and a second position for laying filament on said motor in a plane substantially perpendicular to the plane of said track means; and

means for moving said filament laying means in the plane of said track means whereby the relative speeds of the turntable and the filament laying means deter-mine the pattern of the filament laid on said motor.

9. Apparatus for winding a filament casing on a stationary solid propellant rocket motor, comprising:

a framework positionable about said motor;

a circular rail mounted on said framework above said motor;

a turntable mounted for movement on said rail;

means for moving said turntable on said rail, said means including motor means mounted on said turntable; I

a support suspended from said turntable;

track means mounted on said support at an angle with the vertical and positioned about said motor whereby said track means is rotated about said motor by movement of said turntable;

means connected to said support and to said track means for varying said angle between said track means and the vertical;

a plurality of Winding carriages mounted on said track means for movement in the plane of said track means, each of said Winding carriages including filament laying means having a first position for laying filament on said motor in a plane parallel to the plane of said track means and a second position for laying filament on said motor in a plane substantially perpendicular to the plane of said track means; and

of said track means whereby the relative speeds of the turntable and the Winding carriages determine the pattern of the filament laid on said motor.

References Cited UNITED STATES PATENTS BILLY S. TAYLOR, Primary Examiner. means for moving said winding carriages in the plane 15 MERVIN STEIN, Examine 

1. APPARATUS FOR WINDING A FILAMENT CASING ON A STATIONARY OBJECT, COMPRISING: A FRAMEWORK POSITIONABLE ADJACENT SAID OBJECT; MEANS MOUNTED ON SAID FRAMEWORK ABOVE SAID OBJECT, SAID MEANS INCLUDING MEANS ROTATABLE COMPLETELY AROUND SAID OBJECT; TRACK MEANS SUSPENDED FROM SAID MOVABLE MEANS, SAID TRACK MEANS BEING POSITIONABLE ABOUT SAID OBJECT; MEANS FR LAYING A FILAMENT ON SAID OBJECT, SAID FILAMENT LAYING MEANS BEING MOUNTED ON SAID TRACK MEANS FOR TRAVEL THEREON; AND MEANS FOR VARYING THE ANGLE BETWEN SAID TRUCK MEANS AND SAID MOVABLE MEANS. 